1. Field of the Invention
This invention relates to an ultrasonic diagnostic probe having a transducer array capable of turning around its aperture axis and having a convex lens comprising a viscous resin upon the aperture.
2. Description of the Related Arts
In order to diagnose an internal objects, such as an internal organ of human body, an ultrasonic tomography has been observed by the use of an ultrasonic probe which is provided with an ultrasonic transducer array for transmitting an ultrasonic sound towards the internal organ to be observed and then receiving an ultrasonic sounded reflected the internal organ. A tomographic image is obtained along the alignment of the transducer array. Some ultrasonic probes are used in contact with the surface of the human body. However, some probes are inserted as an endscope into the human body cavity where the ultrasonic transducer, i.e. the array, must be turned around its apparent axis in order to attain more objects image. Furthermore, a convex lens formed of a solid resin is provided upon the surface of the transducer array so that the ultrasonic beam is focused at a predetermined proper distance from the transducer. The ultrasonic probe used as the endscope must be of course small in size so as to be easily inserted into the body cavity. A typical prior art probe of such structure shown in FIG. 1 has been disclosed by Ito on Japanese Laid-on Patent Publication Hei 2-206450. Ultrasonic transducer 15 having a convex lens is mounted on a cylindrical support 14, 14a, and is rotatable by selectively pulling a string 22 fixed to sides of the support cylinder 14a.
Problem of the FIG. 1 probe structure is in that an O-ring 20 is required to seal between the ultrasonic transducer 12 and the probe case 16 while the ultrasonic transducer is kept rotatable along O-ring 20. The O-ring is not perfect to protect the sealing from the environment in the human body. Rotation of transducer 15 directly contacting the human organ may injure the wall of the human internal organ.